Food Flavours Q&A
by Tan Lee Hoon 1. Vanilla is the most commonly used flavour for enhancing sweet products. Describe the characteristics of vanilla beans from which the vanilla flavour is sourced. Vanilla beans are the fruit of the orchid Vanilla fragrans. Their characteristic flavour and odour are determined by the region in which the beans are grown, the length of growth time responsible for the development of flavour precursors, and post-harvesting processing.
Regional processing methods significantly affect the quality and profile of the resulting bean flavour. The four most common processing methods - Bourbon, Mexican, Tahitian and Java Indonesian - vary in the length of time beans are grown before picking; duration of drying; and the drying method used, which can include sun-roasting and fire-curing.
Vanillin is the most abundant of the 300 flavour components found in cured vanilla beans, but vanilla quality isn't based entirely on its vanillin content. Non-vanillin volatile and non-volatile flavour components also make up this complex flavour. An aroma profile common to all vanillas is described as sharply acidic with slightly bitter back notes and a pronounced pungency. However, vanillas have characteristic flavours and aromas based on their country of origin.
Processing Method
Country of Origin
Characteristic Flavours and Aromas
Bourbon-processed vanilla beans
Madagascar and the Comoro Islands
-Have a high-vanillin-content vanilla -Rich, smooth, rummy and full-bodied
Mexican vanilla beans
Mexico
-Have a lower vanillin content and the vanilla lacks the body associated with the bourbon beans -Sharp, slightly pungent, woody, resinous, sweet and spicy
Tahitian vanilla beans
Tahiti
-Distinctively sweet, very fragrant and perfume-like, with coumarinic flavour and heliotropine notes
Java vanilla beans
Indonesia
-Deep, full-bodied, harsh, smoky and phenolic
2. Describe the process of extracting vanilla form its beans. Vanilla extract is extracted from the beans by using solvents such as alcohol, propylene glycol or glycerine. Single-fold extracts must contain 7.5 grams of moisture-free vanilla beans per 100 ml. A double-fold vanilla is an extraction prepared from double the quantity of beans. The maximum concentration prepared directly from beans is a four-fold. More highly folded products can be prepared by dissolving a calculated weight of oleoresin vanilla in alcohol or propylene glycol. Oleoresin vanilla is a dark brown semi-fluid extract obtained by solvent extraction of chopped beans under a vacuum. Vanilla also can be spray-dried onto a carrier for dry-mix applications, encapsulated or plated onto sugar.
3. Imitation vanilla flavourings can be made from numerous ingredients, such as essential oils, and natural and artificial flavours. They provide a range of flavour profiles for a variety of applications. These flavour blends can be formulated to be very high in strength for low usage and consistent quality. Since natural vanilla extract can be expensive, these flavourings can translate into significant cost savings. Name some examples of artificial vanilla.
Type
Flavour profile
Synthetic vanillin
Vanilla-like odour
Ethyl vanillin
Intense, vanilla-like odour; has a more powerful flavour than vanillin
Veratraldehyde
Herbaceous and warm
Heliotropine
Sweet, spicy and floral
Anisyl acetate
Powdery and floral
Vanitrope
Warm, spicy medicinal sweetness
4. What are the basic types of sweet, brown flavours? Sweet, brown flavours includes those flavours having the connotations of roasted, burnt or caramelized flavour systems. They can be extracted from botanicals and supplemented with other natural and artificial flavours, or they can be created by a reaction process. Flavours within this category include brown sugar, graham cracker, malt, honey, maple, molasses, caramel, butterscotch, coffee and chocolate.
5. Describe the process of making malt extract. Malt extract is made from germinated barley seed that produces enzymatic activity responsible for the flavour. Drying the grain provides shelf life and develops the flavour and colour. To protect the enzymes, the heating must be carried out carefully, at low temperatures, while the malt is high in moisture. Once the moisture level has been reduced, the temperature is increased to bring about the flavour and colour changes. By varying the amount and severity of drying, a range of malt colours and flavours can be produced. Malt products range from the lightly coloured, mild-flavoured versions with high enzyme activity, to dark-coloured, highly flavoured types with little enzyme activity. Enzyme activity can prove an important factor in the development of baked goods.
6.What are the types of syrups typically found in nature?
Type
Source
Flavour profile
Honey
-Plant pollen -A complex flavour resulting from the sugars, acids, tannins, and volatile and non-volatile components within it.
-A sweetener with a characteristic flavour -Darker-coloured honey is stronger in flavour -Light-coloured honey is generally very mild
Maple syrup
-Sap of black maple and sugar maple trees -Sap is concentrated through an evaporative process, which produces some glucose and fructose upon inversion at a low pH, and which thickens it and intensifies the flavour. -One group of flavouring components comes from the ligneous materials from the sap, but a second group is formed by the caramelization of sugars.
-A characterizing sweet brown flavour
Molasses
-Concentrated extract of sugar cane -Whole sugar-cane juice is evaporated into a high-density syrup containing a major portion of the solids, then put through a crystallization step that removes sucrose crystals from the liquid phase. The remaining liquid undergoes additional recrystallization steps that concentrate the molasses content.
-A strongly flavoured, slightly sweet syrup
7.Describe the processing of cocoa beans that gives rise to chocolate flavour. Chocolate chemical precursors are developed through the microbial and enzymatic fermentation of the cocoa beans and pulp. The drying and roasting of the beans then converts the flavour precursors to a complex mixture of many aromatic compounds including esters, lactones, pyrazines, hydrocarbons, alcohols, aldehydes, ketones, phenols, sulfides and more. Milk powder, whey, and natural and artificial flavours also are added to alter the flavour profile. Much variation occurs in chocolate's flavour profile, ranging anywhere from a deep, dark baker's chocolate to a sweet, milky version.
An alkali treatment (Dutching) will neutralize some of the acids to produce a more bitter and astringent product in the pH range of 6.0 to 8.5. With its darker (or even reddish) colour and full, rich flavour, Dutch cocoa is well-suited to baked goods and cake mixes and coatings.
Non-alkalized cocoa (referred to as natural processed cocoa) has a fruitier and acidic cocoa flavour, falling in the neutral-to-slightly-acidic pH range of 5.1 to 5.9. The mild fruity notes come through especially well in high-moisture or fat-based systems.
Chocolate flavours typically contain actual chocolate, or extracts and distillates from the cocoa beans. Artificial chocolate is difficult to make without any real chocolate extractive components because of the complexity of the flavour. Vanilla and vanillin are commonly added to enhance the flavour of chocolate. They also are the primary source of flavour in white chocolate, which is a blend of cocoa butter, sugar and milk.
8.Describe how coffee flavour is derived from chemical reactions that occur during the processing of coffee beans. Coffee flavour is derived from the berries picked from the evergreen trees Coffea arabica L. and Coffea robusta L. These fleshy berries are dried, hulled and fermented into green coffee beans. Roasting reduces their acidity and develops the aromatic oils that give coffee its characteristic flavour and door.
Coffee flavour depends on bean variety, country of origin, and climatic and soil conditions. Arabica coffee accounts for most of the world's coffee production, and is superior in flavour to the Robusta variety. With its rougher, more earthy flavour, Robusta coffee lacks the delicacy and subtlety of the Arabica beans.
A coffee’s delicacy and richness is determined by its degree of roasting.
Degree of Roasting
Purpose
Light roast
Used for beans with subtle flavours that could be ruined or lost by using a stronger roast
Medium roast
Has more flavour and aroma than a light roast
Dark roast
Used for beans with very strong flavour and aroma
Coffee contains more than 300 compounds. Coffee flavours can be describe as acidic, full-bodied, mellow, mocha, soft, nutty, rich, smooth, acidic, spicy, smoky, winey, heavy, chocolate, bright and earthy.
9.How is caramel flavour developed? Heat is applied to sucrose above its melting point to catalyze the reaction of caramelization. Sugar breakdown products create a mixture of aldehydes and ketones and, most importantly, furanones. These can be characterized as caramel-like, sweet, fruity, butterscotch, nutty or burnt, and are the backbone of the caramel flavour. Maltol, ethyl maltol and cyclotene are components commonly found in caramel flavours. Caramel candy's flavour comes from heating and concentrating sugar and milk, so simulated caramel flavourings often are enhanced by added dairy notes. Caramelization occurs in baking and cereal manufacturing, and the product base can be enhanced by adding caramel-type flavours.
10.What are the common forms of fruit flavours and how do they differ from one another? Fruit flavour can be added either in the form of whole fruit, fruit juice, juice concentrates, purees, pastes, dehydrates, spray-dried powders and flavours.
Form of fruit flavour
Description
Whole fruit (containing seeds)
-Contains green and bitter components
Unprocessed fruit
-Contains active enzymes that can cause off-flavours and off-colours over time if they aren't inactivated
Fruit juice
-Obtained by the mechanical pressing of ripe fruit -Flavour greatly depends on the quality and degree of ripeness found in the original fruit -Contain extraneous matter, such as proteins, pectins and gums, that contribute cloudiness and viscosity changes -Often contain too much water in relation to their flavour strength, so they're concentrated
Expressed juice
-Would not taste like the actual whole fruit because the characteristic volatile components are found in very low levels
Fresh-fruit flavour
-Can be achieved by blending juice with aromatics recovered from the rest of the fruit
Natural and synthetic flavours
-Can be added to juice to boost flavour and reduce expense
Dehydrated fruit juice
-Contributes real fruit, but its flavour is often lost or its character changed due to the heat treatment -Can lump and become difficult to work with due to its hygroscopic nature
Freeze-dried juice
-Has a much higher flavour quality, but is typically more expensive
11.Briefly describe some processing steps involved in forming fruit flavours.
a. Pasteurization - Used to reduce potential spoilage, but it involves high heat which can result in heat-catalyzed chemical reactions of the flavour compounds.
b. Concentration via vacuum distillation – Separates solid matter from the aromatic substances. These can be partially recovered and added to the concentrate, but the finished product will still be deficient in top notes.
c. Freeze concentration – Uses no heat, so the finished product's profile is closer to real fresh fruit.
12.How are organic acids in fruits useful in terms of enhancing the fruit flavour? Organic acids occur naturally in fruits, giving them their distinguishing flavour and bite. Each individual acid will enhance the fruit flavour differently, depending on the acid used to enhance it. Some examples are given in the table below:
Type/Blend of Organic Acid
Fruit flavour enhanced
Citric acid
Cherry, strawberry, grape
Malic acid
Apple, pear
Malic + tartaric acids
Raspberry, grape
13.Why is there a need for using nut flavours that are not nut-based? Many nuts contain allergens, so a great need exists for flavours that aren't nut-based. However, since natural flavours require the use of actual nut extractives, it's not easy to develop an all-natural flavour that is allergen-free. Flavours can come in the form of nut oils and nut flavours.
Nut oils, containing the flavour volatiles of the nut itself, can be expressed and used as a delicate flavouring agent. Nut oils are typically mild in flavour, and must be used in large quantities to contribute any significant flavour properties in most processed foods. Their many unsaturated fatty acids are subject to rancidity and off-flavours.
Nut flavour can be developed from synthetic ingredients that not only convey a nutty characteristic but can simulate the specific nut, such as a filbert, hazelnut, cashew or pecan. Because nuts typically feature high fat levels, the flavour and mouthfeel of fat is typically associated with the true nut flavour. Nut flavoured food will therefore have a better flavour delivery and mouthfeel if a small amount of fat or oil is added.
14.What are spices? Spices are defined as natural vegetable products used for flavouring, seasoning and imparting aroma to foods. Small quantities of spices add dimension to a food product, and their connotations of naturalness appeal to the consumer. However, spices vary in strength and flavour profile. Their flavour is often less evenly distributed within the food matrix. They can even represent a microbiological hazard or lose flavour strength upon storage. Occasionally, a large spice volume can make the food matrix muddied or speckled and bitter-tasting.
15.Dairy flavours. Explain. Many sweet products are made with a substantial percentage of dairy products. Milk and cream have low flavour levels. Yet, the flavours they do possess come from proteins, lactose, salts, free fatty acids, dimethyl sulfide, and the carbonyls acetaldehyde, acetone and formaldehyde.
To accurately flavour a system that might contain substantially less dairy products (or none at all), the notes of milk, cream and cream cheese might need to be added as the characterizing flavour or for background notes. Dairy and butter flavours can be artificially simulated from butter-flavoured compounds such as diacetyl and butyric acid, made naturally through enzymatic activity such as the lipolization of butter oil, natural starter distillates or products of fermentation. For a flavour to be perceived as a dairy fat flavour, there must be some compensation to the mouthfeel with either the addition of vegetable oil or some type of fat mimetic system.
by Tan Lee Hoon
1. Vanilla is the most commonly used flavour for enhancing sweet products. Describe the characteristics of vanilla beans from which the vanilla flavour is sourced.
Vanilla beans are the fruit of the orchid Vanilla fragrans. Their characteristic flavour and odour are determined by the region in which the beans are grown, the length of growth time responsible for the development of flavour precursors, and post-harvesting processing.
Regional processing methods significantly affect the quality and profile of the resulting bean flavour. The four most common processing methods - Bourbon, Mexican, Tahitian and Java Indonesian - vary in the length of time beans are grown before picking; duration of drying; and the drying method used, which can include sun-roasting and fire-curing.
Vanillin is the most abundant of the 300 flavour components found in cured vanilla beans, but vanilla quality isn't based entirely on its vanillin content. Non-vanillin volatile and non-volatile flavour components also make up this complex flavour. An aroma profile common to all vanillas is described as sharply acidic with slightly bitter back notes and a pronounced pungency. However, vanillas have characteristic flavours and aromas based on their country of origin.
-Rich, smooth, rummy and full-bodied
-Sharp, slightly pungent, woody, resinous, sweet and spicy
2. Describe the process of extracting vanilla form its beans.
Vanilla extract is extracted from the beans by using solvents such as alcohol, propylene glycol or glycerine. Single-fold extracts must contain 7.5 grams of moisture-free vanilla beans per 100 ml. A double-fold vanilla is an extraction prepared from double the quantity of beans. The maximum concentration prepared directly from beans is a four-fold. More highly folded products can be prepared by dissolving a calculated weight of oleoresin vanilla in alcohol or propylene glycol. Oleoresin vanilla is a dark brown semi-fluid extract obtained by solvent extraction of chopped beans under a vacuum. Vanilla also can be spray-dried onto a carrier for dry-mix applications, encapsulated or plated onto sugar.
3. Imitation vanilla flavourings can be made from numerous ingredients, such as essential oils, and natural and artificial flavours. They provide a range of flavour profiles for a variety of applications. These flavour blends can be formulated to be very high in strength for low usage and consistent quality. Since natural vanilla extract can be expensive, these flavourings can translate into significant cost savings. Name some examples of artificial vanilla.
4. What are the basic types of sweet, brown flavours?
Sweet, brown flavours includes those flavours having the connotations of roasted, burnt or caramelized flavour systems. They can be extracted from botanicals and supplemented with other natural and artificial flavours, or they can be created by a reaction process. Flavours within this category include brown sugar, graham cracker, malt, honey, maple, molasses, caramel, butterscotch, coffee and chocolate.
5. Describe the process of making malt extract.
Malt extract is made from germinated barley seed that produces enzymatic activity responsible for the flavour. Drying the grain provides shelf life and develops the flavour and colour. To protect the enzymes, the heating must be carried out carefully, at low temperatures, while the malt is high in moisture. Once the moisture level has been reduced, the temperature is increased to bring about the flavour and colour changes. By varying the amount and severity of drying, a range of malt colours and flavours can be produced. Malt products range from the lightly coloured, mild-flavoured versions with high enzyme activity, to dark-coloured, highly flavoured types with little enzyme activity. Enzyme activity can prove an important factor in the development of baked goods.
6. What are the types of syrups typically found in nature?
-A complex flavour resulting from the sugars, acids, tannins, and volatile and non-volatile components within it.
-Darker-coloured honey is stronger in flavour
-Light-coloured honey is generally very mild
-Sap is concentrated through an evaporative process, which produces some glucose and fructose upon inversion at a low pH, and which thickens it and intensifies the flavour.
-One group of flavouring components comes from the ligneous materials from the sap, but a second group is formed by the caramelization of sugars.
-Whole sugar-cane juice is evaporated into a high-density syrup containing a major portion of the solids, then put through a crystallization step that removes sucrose crystals from the liquid phase. The remaining liquid undergoes additional recrystallization steps that concentrate the molasses content.
7. Describe the processing of cocoa beans that gives rise to chocolate flavour.
Chocolate chemical precursors are developed through the microbial and enzymatic fermentation of the cocoa beans and pulp. The drying and roasting of the beans then converts the flavour precursors to a complex mixture of many aromatic compounds including esters, lactones, pyrazines, hydrocarbons, alcohols, aldehydes, ketones, phenols, sulfides and more. Milk powder, whey, and natural and artificial flavours also are added to alter the flavour profile. Much variation occurs in chocolate's flavour profile, ranging anywhere from a deep, dark baker's chocolate to a sweet, milky version.
An alkali treatment (Dutching) will neutralize some of the acids to produce a more bitter and astringent product in the pH range of 6.0 to 8.5. With its darker (or even reddish) colour and full, rich flavour, Dutch cocoa is well-suited to baked goods and cake mixes and coatings.
Non-alkalized cocoa (referred to as natural processed cocoa) has a fruitier and acidic cocoa flavour, falling in the neutral-to-slightly-acidic pH range of 5.1 to 5.9. The mild fruity notes come through especially well in high-moisture or fat-based systems.
Chocolate flavours typically contain actual chocolate, or extracts and distillates from the cocoa beans. Artificial chocolate is difficult to make without any real chocolate extractive components because of the complexity of the flavour. Vanilla and vanillin are commonly added to enhance the flavour of chocolate. They also are the primary source of flavour in white chocolate, which is a blend of cocoa butter, sugar and milk.
8. Describe how coffee flavour is derived from chemical reactions that occur during the processing of coffee beans.
Coffee flavour is derived from the berries picked from the evergreen trees Coffea arabica L. and Coffea robusta L. These fleshy berries are dried, hulled and fermented into green coffee beans. Roasting reduces their acidity and develops the aromatic oils that give coffee its characteristic flavour and door.
Coffee flavour depends on bean variety, country of origin, and climatic and soil conditions. Arabica coffee accounts for most of the world's coffee production, and is superior in flavour to the Robusta variety. With its rougher, more earthy flavour, Robusta coffee lacks the delicacy and subtlety of the Arabica beans.
A coffee’s delicacy and richness is determined by its degree of roasting.
9. How is caramel flavour developed?
Heat is applied to sucrose above its melting point to catalyze the reaction of caramelization. Sugar breakdown products create a mixture of aldehydes and ketones and, most importantly, furanones. These can be characterized as caramel-like, sweet, fruity, butterscotch, nutty or burnt, and are the backbone of the caramel flavour. Maltol, ethyl maltol and cyclotene are components commonly found in caramel flavours. Caramel candy's flavour comes from heating and concentrating sugar and milk, so simulated caramel flavourings often are enhanced by added dairy notes. Caramelization occurs in baking and cereal manufacturing, and the product base can be enhanced by adding caramel-type flavours.
10. What are the common forms of fruit flavours and how do they differ from one another?
Fruit flavour can be added either in the form of whole fruit, fruit juice, juice concentrates, purees, pastes, dehydrates, spray-dried powders and flavours.
-Flavour greatly depends on the quality and degree of ripeness found in the original fruit
-Contain extraneous matter, such as proteins, pectins and gums, that contribute cloudiness and viscosity changes
-Often contain too much water in relation to their flavour strength, so they're concentrated
-Can lump and become difficult to work with due to its hygroscopic nature
11. Briefly describe some processing steps involved in forming fruit flavours.
a. Pasteurization - Used to reduce potential spoilage, but it involves high heat which can result in heat-catalyzed chemical reactions of the flavour compounds.
b. Concentration via vacuum distillation – Separates solid matter from the aromatic substances. These can be partially recovered and added to the concentrate, but the finished product will still be deficient in top notes.
c. Freeze concentration – Uses no heat, so the finished product's profile is closer to real fresh fruit.
12. How are organic acids in fruits useful in terms of enhancing the fruit flavour?
Organic acids occur naturally in fruits, giving them their distinguishing flavour and bite. Each individual acid will enhance the fruit flavour differently, depending on the acid used to enhance it. Some examples are given in the table below:
13. Why is there a need for using nut flavours that are not nut-based?
Many nuts contain allergens, so a great need exists for flavours that aren't nut-based. However, since natural flavours require the use of actual nut extractives, it's not easy to develop an all-natural flavour that is allergen-free. Flavours can come in the form of nut oils and nut flavours.
Nut oils, containing the flavour volatiles of the nut itself, can be expressed and used as a delicate flavouring agent. Nut oils are typically mild in flavour, and must be used in large quantities to contribute any significant flavour properties in most processed foods. Their many unsaturated fatty acids are subject to rancidity and off-flavours.
Nut flavour can be developed from synthetic ingredients that not only convey a nutty characteristic but can simulate the specific nut, such as a filbert, hazelnut, cashew or pecan. Because nuts typically feature high fat levels, the flavour and mouthfeel of fat is typically associated with the true nut flavour. Nut flavoured food will therefore have a better flavour delivery and mouthfeel if a small amount of fat or oil is added.
14. What are spices?
Spices are defined as natural vegetable products used for flavouring, seasoning and imparting aroma to foods. Small quantities of spices add dimension to a food product, and their connotations of naturalness appeal to the consumer. However, spices vary in strength and flavour profile. Their flavour is often less evenly distributed within the food matrix. They can even represent a microbiological hazard or lose flavour strength upon storage. Occasionally, a large spice volume can make the food matrix muddied or speckled and bitter-tasting.
15. Dairy flavours. Explain.
Many sweet products are made with a substantial percentage of dairy products. Milk and cream have low flavour levels. Yet, the flavours they do possess come from proteins, lactose, salts, free fatty acids, dimethyl sulfide, and the carbonyls acetaldehyde, acetone and formaldehyde.
To accurately flavour a system that might contain substantially less dairy products (or none at all), the notes of milk, cream and cream cheese might need to be added as the characterizing flavour or for background notes. Dairy and butter flavours can be artificially simulated from butter-flavoured compounds such as diacetyl and butyric acid, made naturally through enzymatic activity such as the lipolization of butter oil, natural starter distillates or products of fermentation. For a flavour to be perceived as a dairy fat flavour, there must be some compensation to the mouthfeel with either the addition of vegetable oil or some type of fat mimetic system.